[I[t looks like separate and distinction lineages of R. rattus piggybacked on the expansion of humans….

We’re speaking of the the black rat, Rattus rattus (“also known,” notes the paper, as the ‘House,’ ‘Roof,’ and ‘Ship’ Rat), which is one of the world’s most widely distributed animals “and most destructive of all animal pests.”) Prior to this paper, the evolutionary spread of R. rattus had apparently gone largely unstudied. The authors parsed the lineage via mitochondrial DNA and found that the black rat’s outmigration from the Middle East overlaps neatly with ours, expanding both northwest to Europe and east to Asia, and from those two regions across the Atlantic to the Western Hemisphere and across the Pacific to that ocean’s countless archipelagoes. It came close in our footsteps — or perhaps in our baggage. It reached Romans before the Romans did and Britain, presumably by ship, by the 4th century; later it passed us the plague. It’s a bit odd reading all this. Rats seem to be a pest that somehow would have gone before us, or invaded from afar; it seems like something inflicted upon us. Yet they appear to have followed us much as jet-trail trails jet.

Some — or some of their descendants — ended up in the Guangdong hills from which Hessler’s Simmer Rat with Black Beans, in 2000, supposedly made its way the Highest Ranking Wild Flavor Restaurant, where Hessler meets it in a dish. Rats had become haut cuisine.

“Many people come from faraway places [to eat these rats],” Zhong Qingjian [the restaurant owner] told me. “They come form Guangzhou, Shenzhen, Hong Kong, Macao. One customer came all the way from American with her son. they were visiting relatives in Luogang, and the family brought them here to eat. She said you couldn’t find this kind of food in America.”

Rattus rattus occupied most of the menu there and at several other restaurants in Guangdong. Hessler watched earlier that morning as peasants came down out of the hills “looking to get a piece of the rat business.”

They came on mopeds, on bicycles, and on foot. All of them carried burlap sacks of squirming rats that had been trapped on their farms.

Hessler describes, skeptically, how he is told the rats in those hills are a cleaner sort — clean country rats, essentially, who feed on things other than garbage. The PLoS One paper suggests this might actually be so, as it mentions a hill species spun off from Rattus rattus, Rattus tiomanicus, the Malaysian wood rat, that is said to avoid towns and villages; and R tiomanicus is said to live mainly on islands just offshore from the coast close to Guangdong; conceivably it also lived in hills ashore, and Hessler had one of them. Or maybe I just feel bad for him and want it to be so. At his second rat meal, having ordered Spicy and Salty Mountain Rat, he is urged to choose the cut.

I followed one of the kitchen workers to a shed behind the restaurant, where cages were stacked atop one another. Each cage contained more than thirty rats. The shed did not smell good. The worker pointed at a rat.

‘How about this one?’ he said.

‘Um, sure.’

He put on a glove, opened the cage, and picked up the chosen rat. It was about the size of a softball. ‘Is it O.K.?’ he said.

‘Yes.”

‘Are you certain?’

The rat gazed at me with beady eyes.

I nodded.

Suddenly, the worker flipped his wrist, swung the rat into the air by the tail and let go. The rat made a neat arc. There was a soft thud when its head struck the cement floor. There wasn’t much blood.

Here’s The Thing With Ad Blockers

We get it: Ads aren’t what you’re here for. But ads help us keep the lights on. So, add us to your ad blocker’s whitelist or pay $1 per week for an ad-free version of WIRED. Either way, you are supporting our journalism. We’d really appreciate it.